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I am having some quotes to build a machine shed here at the farm. Now I need bigger but have to draw the line somewhere. So for now I'm sticking with 30x40. I am thinking of leaving one 40' long wall open. So normally this would be posts 10' on center. In effort to eliminate axle to post fatigue I am toying with the idea of stretching it out further. 1 company offered to span 20' with 4 2x10's. Another wants to use lvl lam beams but he will stretch it out 20'. The third guy said he doesn't recommend any further than 13' and doesn't think an engineer will sign off on lvl or anything for 20'. So to back things in like I want to 3 13' bays really don't help much. i would like to back in atleast 4 tractors and the posts will suck at 13'. Whats your all's thoughts on stretching that header 20' with either 4 2x10's or a lvl beam? I was just going to deal with 10' centers but cost is about the same and I would like more open but don't want to sacrifice integrity of the structure. I'm not paying 1000 for engineer. Also here snow load is a minimum I'm Missouri compared to up North. Whatcha think? The two guys say they do this for sliding door headers a lot.

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I have 20' doors on eave and gable side if my building. If they can span that with a header I would think they could spam a 20' opening on an open front building.

There is NO weight on the gable end. The truss carries it all just like it does on the other trusses. If the truss couldn't carry the weight, you would need a post in the center of every truss in your pole buildings.

Onthe long sidewall, the truss needs something to sit on, hence the need for a large beam if there is no post.

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If I'm gonna have this built they won't want to mess with steel. **** I have 2 sticks of 6x10 box tubing I picked up on a job that would work. But than fastening wood trusses to that would be a little more work. I doubt a pole barn builder would want to do it. I think the beam should carry the load. I am more concerned about that center post. I think that's a lot of weight sitting mostly on 1 post.

If I'm gonna have this built they won't want to mess with steel. **** I have 2 sticks of 6x10 box tubing I picked up on a job that would work. But than fastening wood trusses to that would be a little more work. I doubt a pole barn builder would want to do it. I think the beam should carry the load. I am more concerned about that center post. I think that's a lot of weight sitting mostly on 1 post.

Make the post out of steel

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Hire a structural engineer that specializes in timber design. Might cost $1000 but he stamps and seals his design and he's on the hook for any failure. Free advice on a forum is just someones opinion. If your buying trusses, the truss company engineer can probably help you.

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we have a 20' lam w/2x slider on the eve side as part of original package ..building .was already 3 sizes too small so before finished had wagon shed added they did not have print and could not achieve 4/12 so at 1.5/12 for snow load they have poles EVERY 8'.5 both ways...about worthless excepting 2 man pERFECT wagon spotting

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i built a pole barn and spanned the doors 12 ft.with 2x10 hardwood then a kid who worked for me took out apost with a truck. we lifted the collapsed roof back in place and sistered a 1/2" x 8 flat steel to it to span the 24 ft. i had him drill 1/2" holes thru the steel then lagged it together. he was tired after drilling holes every 8 inches. so just span with steel

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For what it's worth...my barn is a 2/12or less pitch has a glue lam beam for the center beam, with 24 foot bcis as the purlins so with a lot of weight with snow load...I'll take a picture later... Its a clear span at was 20 now 30 feet....

Hire a structural engineer that specializes in timber design. Might cost $1000 but he stamps and seals his design and he's on the hook for any failure. Free advice on a forum is just someones opinion. If your buying trusses, the truss company engineer can probably help you.

Also dont matter what anybody here thinks if doesnt meet whatever local codes you may have. And check with pole barn builders they may work with you or you may have to get firm with them as far as putting steel span in, after all its your money and you are the customer.

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I have a 96x50 clear span with a 22ft door on eve side, header is 2x12s. Can't recall how many, I think 4 but might be 5. Both sides are double 6x6 posts with a chunk of 2x spiked on the side under the header to add support. As said I would get your truss engineer to design your header.

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Both places that said they would do this are builders and claim they do this a lot. They act like its not that big of a deal. The one guy builds his posts out of 2x6's. He said he would sandwich the lam between 6 2x6's turned sideways to make a 5 1/2" x 9" post with through bolts for wind load. I liked this idea. My other option would be to make the whole building a little longer make one opening in the middle bigger and two smaller openings on each end. So maybe that would work and be better? No matter what having a eve wall open the posts are a pain in the butt. I just need to make maximum space available. So If I make it 40' it will have tractors/trucks wall to wall. One of the guys that offered the 20' span with lams is a friend of mine and he does lots of barns that are engineered and have permits, so he should know what will work. I still just don't know if I like it. I think a steel post would make me feel better about it. I also thought about doing 3 bays of 16' and just make the darn thing 48'. This would work out ok for everything.

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You will need to know the snow loads for your area and consult your local lumber yard. There are tables of specifications published that allow them to look up your requirements and order the beam. 20' is no problem with LVL or glulam, just has to be sized right.

I think the code requirements will hinge on what the snow load is, up here is 55# per square foot snow load and then 10# dead load, when you start adding all that up it puts a huge load on the beam, and a deeper building has more load.

There are some tables on line, and some plans at the state ag extension sites

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You can also get laminated post. 2x glued together. Or use a bigger center post. With 4" concrete in bottom. But I don't see a problem with 20' opening as long as you laminate . Multiple 2x. Or lvl. A 20' opening would sure be nice

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Interests:Farm 1600 acres,milk 700 cows run mainly RED(gotta have a few others to make you appreciate the red ones even more)bought the '46 Farmall A in family since '52 when I was 17. Currently have A, C, Super C,230, M, 400,450 and an F30 adopted from my Wife's side of the family. Wish I had bought the 450 i grew up with, hindsight is 2020

Your Darn right it would be. I hadn't even considered it until both of them talked me out of 10' center posts right away. At first I was skeptical but it would sure be nice.

So lets try this another way. If you had a machine shed that had the long wall open what spacing would you put between posts? I need to be able to back in cab tractors and small combine and dump truck. Would like to have atleast 1 opening big enough to back in discbine or drill which are 13-14'. need to keep my building around 40-50' for cost. And I should add that I am trying not to keep a gable wall open because of its location and because that's the whole problem I have now. Whatever I want is always buried behind everything and have to move 3 tractors to get the one I need.

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Interests:Farm 1600 acres,milk 700 cows run mainly RED(gotta have a few others to make you appreciate the red ones even more)bought the '46 Farmall A in family since '52 when I was 17. Currently have A, C, Super C,230, M, 400,450 and an F30 adopted from my Wife's side of the family. Wish I had bought the 450 i grew up with, hindsight is 2020

Both ends have a 28' openings and one side has a 17' opening. The trusses (wood) are on 9' centers and it has 2x4" studs on edge on 2' centers for the roofing tin. Posts and truss are bolted and nailed

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Yes, I trust what he says. But it never hurts to get others opinions. I figure most guys on here have barns and use them. I would go a little shorter if I could figure out how to make it work. I just don't want to wind up with too much wasted space between each tractor, and certainly don't want a post right in the middle of the place I want to back into. I told my buddy I am going to make a sliding track system to where you just slide the post to where you need it at that time. LOL